Karl Ferdinand Braun

Karl Ferdinand Braun (June 6, 1850 - April 20, 1918) was a German physicist.

Born in Fulda. Educated at the University of Marburg and the University of
Berlin, receiving his Ph.D. in 1872. In 1874 he discovered the point-contact
rectifier effect. He became director of the Physical Institute and professor
of physics at Strasbourg in 1895. In 1897 he built the first cathode-ray
tube oscilloscope, the CRT is still called the "Braun tube" at the
University of Karlsruhe, Germany. He also worked on wireless telegraphy from
1898, inventing the crystal rectifier and Guglielmo Marconi admitted to
'borrowing' from Braun's patents. In 1909 Braun shared the Nobel Prize for
physics with Marconi for "contributions to the development of wireless
telegraphy."

Braun was detained while in America because of his German citizenship when
the U.S. entered WWI in 1917. He died before the war ended in 1918.